Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * arch/m68k/atari/stram.c: Functions for ST-RAM allocations |
| 3 | * |
| 4 | * Copyright 1994-97 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de> |
| 5 | * |
| 6 | * This file is subject to the terms and conditions of the GNU General Public |
| 7 | * License. See the file COPYING in the main directory of this archive |
| 8 | * for more details. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/config.h> |
| 12 | #include <linux/types.h> |
| 13 | #include <linux/kernel.h> |
| 14 | #include <linux/mm.h> |
| 15 | #include <linux/kdev_t.h> |
| 16 | #include <linux/major.h> |
| 17 | #include <linux/init.h> |
| 18 | #include <linux/swap.h> |
| 19 | #include <linux/slab.h> |
| 20 | #include <linux/vmalloc.h> |
| 21 | #include <linux/pagemap.h> |
| 22 | #include <linux/shm.h> |
| 23 | #include <linux/bootmem.h> |
| 24 | #include <linux/mount.h> |
| 25 | #include <linux/blkdev.h> |
| 26 | |
| 27 | #include <asm/setup.h> |
| 28 | #include <asm/machdep.h> |
| 29 | #include <asm/page.h> |
| 30 | #include <asm/pgtable.h> |
| 31 | #include <asm/atarihw.h> |
| 32 | #include <asm/atari_stram.h> |
| 33 | #include <asm/io.h> |
| 34 | #include <asm/semaphore.h> |
| 35 | |
| 36 | #include <linux/swapops.h> |
| 37 | |
| 38 | #undef DEBUG |
| 39 | |
| 40 | #ifdef DEBUG |
| 41 | #define DPRINTK(fmt,args...) printk( fmt, ##args ) |
| 42 | #else |
| 43 | #define DPRINTK(fmt,args...) |
| 44 | #endif |
| 45 | |
| 46 | #if defined(CONFIG_PROC_FS) && defined(CONFIG_STRAM_PROC) |
| 47 | /* abbrev for the && above... */ |
| 48 | #define DO_PROC |
| 49 | #include <linux/proc_fs.h> |
| 50 | #endif |
| 51 | |
| 52 | /* Pre-swapping comments: |
| 53 | * |
| 54 | * ++roman: |
| 55 | * |
| 56 | * New version of ST-Ram buffer allocation. Instead of using the |
| 57 | * 1 MB - 4 KB that remain when the ST-Ram chunk starts at $1000 |
| 58 | * (1 MB granularity!), such buffers are reserved like this: |
| 59 | * |
| 60 | * - If the kernel resides in ST-Ram anyway, we can take the buffer |
| 61 | * from behind the current kernel data space the normal way |
| 62 | * (incrementing start_mem). |
| 63 | * |
| 64 | * - If the kernel is in TT-Ram, stram_init() initializes start and |
| 65 | * end of the available region. Buffers are allocated from there |
| 66 | * and mem_init() later marks the such used pages as reserved. |
| 67 | * Since each TT-Ram chunk is at least 4 MB in size, I hope there |
| 68 | * won't be an overrun of the ST-Ram region by normal kernel data |
| 69 | * space. |
| 70 | * |
| 71 | * For that, ST-Ram may only be allocated while kernel initialization |
| 72 | * is going on, or exactly: before mem_init() is called. There is also |
| 73 | * no provision now for freeing ST-Ram buffers. It seems that isn't |
| 74 | * really needed. |
| 75 | * |
| 76 | */ |
| 77 | |
| 78 | /* |
| 79 | * New Nov 1997: Use ST-RAM as swap space! |
| 80 | * |
| 81 | * In the past, there were often problems with modules that require ST-RAM |
| 82 | * buffers. Such drivers have to use __get_dma_pages(), which unfortunately |
| 83 | * often isn't very successful in allocating more than 1 page :-( [1] The net |
| 84 | * result was that most of the time you couldn't insmod such modules (ataflop, |
| 85 | * ACSI, SCSI on Falcon, Atari internal framebuffer, not to speak of acsi_slm, |
| 86 | * which needs a 1 MB buffer... :-). |
| 87 | * |
| 88 | * To overcome this limitation, ST-RAM can now be turned into a very |
| 89 | * high-speed swap space. If a request for an ST-RAM buffer comes, the kernel |
| 90 | * now tries to unswap some pages on that swap device to make some free (and |
| 91 | * contiguous) space. This works much better in comparison to |
| 92 | * __get_dma_pages(), since used swap pages can be selectively freed by either |
| 93 | * moving them to somewhere else in swap space, or by reading them back into |
| 94 | * system memory. Ok, there operation of unswapping isn't really cheap (for |
| 95 | * each page, one has to go through the page tables of all processes), but it |
| 96 | * doesn't happen that often (only when allocation ST-RAM, i.e. when loading a |
| 97 | * module that needs ST-RAM). But it at least makes it possible to load such |
| 98 | * modules! |
| 99 | * |
| 100 | * It could also be that overall system performance increases a bit due to |
| 101 | * ST-RAM swapping, since slow ST-RAM isn't used anymore for holding data or |
| 102 | * executing code in. It's then just a (very fast, compared to disk) back |
| 103 | * storage for not-so-often needed data. (But this effect must be compared |
| 104 | * with the loss of total memory...) Don't know if the effect is already |
| 105 | * visible on a TT, where the speed difference between ST- and TT-RAM isn't |
| 106 | * that dramatic, but it should on machines where TT-RAM is really much faster |
| 107 | * (e.g. Afterburner). |
| 108 | * |
| 109 | * [1]: __get_free_pages() does a fine job if you only want one page, but if |
| 110 | * you want more (contiguous) pages, it can give you such a block only if |
| 111 | * there's already a free one. The algorithm can't try to free buffers or swap |
| 112 | * out something in order to make more free space, since all that page-freeing |
| 113 | * mechanisms work "target-less", i.e. they just free something, but not in a |
| 114 | * specific place. I.e., __get_free_pages() can't do anything to free |
| 115 | * *adjacent* pages :-( This situation becomes even worse for DMA memory, |
| 116 | * since the freeing algorithms are also blind to DMA capability of pages. |
| 117 | */ |
| 118 | |
| 119 | /* 1998-10-20: ++andreas |
| 120 | unswap_by_move disabled because it does not handle swapped shm pages. |
| 121 | */ |
| 122 | |
| 123 | /* 2000-05-01: ++andreas |
| 124 | Integrated with bootmem. Remove all traces of unswap_by_move. |
| 125 | */ |
| 126 | |
| 127 | #ifdef CONFIG_STRAM_SWAP |
| 128 | #define ALIGN_IF_SWAP(x) PAGE_ALIGN(x) |
| 129 | #else |
| 130 | #define ALIGN_IF_SWAP(x) (x) |
| 131 | #endif |
| 132 | |
| 133 | /* get index of swap page at address 'addr' */ |
| 134 | #define SWAP_NR(addr) (((addr) - swap_start) >> PAGE_SHIFT) |
| 135 | |
| 136 | /* get address of swap page #'nr' */ |
| 137 | #define SWAP_ADDR(nr) (swap_start + ((nr) << PAGE_SHIFT)) |
| 138 | |
| 139 | /* get number of pages for 'n' bytes (already page-aligned) */ |
| 140 | #define N_PAGES(n) ((n) >> PAGE_SHIFT) |
| 141 | |
| 142 | /* The following two numbers define the maximum fraction of ST-RAM in total |
| 143 | * memory, below that the kernel would automatically use ST-RAM as swap |
| 144 | * space. This decision can be overridden with stram_swap= */ |
| 145 | #define MAX_STRAM_FRACTION_NOM 1 |
| 146 | #define MAX_STRAM_FRACTION_DENOM 3 |
| 147 | |
| 148 | /* Start and end (virtual) of ST-RAM */ |
| 149 | static void *stram_start, *stram_end; |
| 150 | |
| 151 | /* set after memory_init() executed and allocations via start_mem aren't |
| 152 | * possible anymore */ |
| 153 | static int mem_init_done; |
| 154 | |
| 155 | /* set if kernel is in ST-RAM */ |
| 156 | static int kernel_in_stram; |
| 157 | |
| 158 | typedef struct stram_block { |
| 159 | struct stram_block *next; |
| 160 | void *start; |
| 161 | unsigned long size; |
| 162 | unsigned flags; |
| 163 | const char *owner; |
| 164 | } BLOCK; |
| 165 | |
| 166 | /* values for flags field */ |
| 167 | #define BLOCK_FREE 0x01 /* free structure in the BLOCKs pool */ |
| 168 | #define BLOCK_KMALLOCED 0x02 /* structure allocated by kmalloc() */ |
| 169 | #define BLOCK_GFP 0x08 /* block allocated with __get_dma_pages() */ |
| 170 | #define BLOCK_INSWAP 0x10 /* block allocated in swap space */ |
| 171 | |
| 172 | /* list of allocated blocks */ |
| 173 | static BLOCK *alloc_list; |
| 174 | |
| 175 | /* We can't always use kmalloc() to allocate BLOCK structures, since |
| 176 | * stram_alloc() can be called rather early. So we need some pool of |
| 177 | * statically allocated structures. 20 of them is more than enough, so in most |
| 178 | * cases we never should need to call kmalloc(). */ |
| 179 | #define N_STATIC_BLOCKS 20 |
| 180 | static BLOCK static_blocks[N_STATIC_BLOCKS]; |
| 181 | |
| 182 | #ifdef CONFIG_STRAM_SWAP |
| 183 | /* max. number of bytes to use for swapping |
| 184 | * 0 = no ST-RAM swapping |
| 185 | * -1 = do swapping (to whole ST-RAM) if it's less than MAX_STRAM_FRACTION of |
| 186 | * total memory |
| 187 | */ |
| 188 | static int max_swap_size = -1; |
| 189 | |
| 190 | /* start and end of swapping area */ |
| 191 | static void *swap_start, *swap_end; |
| 192 | |
| 193 | /* The ST-RAM's swap info structure */ |
| 194 | static struct swap_info_struct *stram_swap_info; |
| 195 | |
| 196 | /* The ST-RAM's swap type */ |
| 197 | static int stram_swap_type; |
| 198 | |
| 199 | /* Semaphore for get_stram_region. */ |
| 200 | static DECLARE_MUTEX(stram_swap_sem); |
| 201 | |
| 202 | /* major and minor device number of the ST-RAM device; for the major, we use |
| 203 | * the same as Amiga z2ram, which is really similar and impossible on Atari, |
| 204 | * and for the minor a relatively odd number to avoid the user creating and |
| 205 | * using that device. */ |
| 206 | #define STRAM_MAJOR Z2RAM_MAJOR |
| 207 | #define STRAM_MINOR 13 |
| 208 | |
| 209 | /* Some impossible pointer value */ |
| 210 | #define MAGIC_FILE_P (struct file *)0xffffdead |
| 211 | |
| 212 | #ifdef DO_PROC |
| 213 | static unsigned stat_swap_read; |
| 214 | static unsigned stat_swap_write; |
| 215 | static unsigned stat_swap_force; |
| 216 | #endif /* DO_PROC */ |
| 217 | |
| 218 | #endif /* CONFIG_STRAM_SWAP */ |
| 219 | |
| 220 | /***************************** Prototypes *****************************/ |
| 221 | |
| 222 | #ifdef CONFIG_STRAM_SWAP |
| 223 | static int swap_init(void *start_mem, void *swap_data); |
| 224 | static void *get_stram_region( unsigned long n_pages ); |
| 225 | static void free_stram_region( unsigned long offset, unsigned long n_pages |
| 226 | ); |
| 227 | static int in_some_region(void *addr); |
| 228 | static unsigned long find_free_region( unsigned long n_pages, unsigned long |
| 229 | *total_free, unsigned long |
| 230 | *region_free ); |
| 231 | static void do_stram_request(request_queue_t *); |
| 232 | static int stram_open( struct inode *inode, struct file *filp ); |
| 233 | static int stram_release( struct inode *inode, struct file *filp ); |
| 234 | static void reserve_region(void *start, void *end); |
| 235 | #endif |
| 236 | static BLOCK *add_region( void *addr, unsigned long size ); |
| 237 | static BLOCK *find_region( void *addr ); |
| 238 | static int remove_region( BLOCK *block ); |
| 239 | |
| 240 | /************************* End of Prototypes **************************/ |
| 241 | |
| 242 | |
| 243 | /* ------------------------------------------------------------------------ */ |
| 244 | /* Public Interface */ |
| 245 | /* ------------------------------------------------------------------------ */ |
| 246 | |
| 247 | /* |
| 248 | * This init function is called very early by atari/config.c |
| 249 | * It initializes some internal variables needed for stram_alloc() |
| 250 | */ |
| 251 | void __init atari_stram_init(void) |
| 252 | { |
| 253 | int i; |
| 254 | |
| 255 | /* initialize static blocks */ |
| 256 | for( i = 0; i < N_STATIC_BLOCKS; ++i ) |
| 257 | static_blocks[i].flags = BLOCK_FREE; |
| 258 | |
| 259 | /* determine whether kernel code resides in ST-RAM (then ST-RAM is the |
| 260 | * first memory block at virtual 0x0) */ |
| 261 | stram_start = phys_to_virt(0); |
| 262 | kernel_in_stram = (stram_start == 0); |
| 263 | |
| 264 | for( i = 0; i < m68k_num_memory; ++i ) { |
| 265 | if (m68k_memory[i].addr == 0) { |
| 266 | /* skip first 2kB or page (supervisor-only!) */ |
| 267 | stram_end = stram_start + m68k_memory[i].size; |
| 268 | return; |
| 269 | } |
| 270 | } |
| 271 | /* Should never come here! (There is always ST-Ram!) */ |
| 272 | panic( "atari_stram_init: no ST-RAM found!" ); |
| 273 | } |
| 274 | |
| 275 | |
| 276 | /* |
| 277 | * This function is called from setup_arch() to reserve the pages needed for |
| 278 | * ST-RAM management. |
| 279 | */ |
| 280 | void __init atari_stram_reserve_pages(void *start_mem) |
| 281 | { |
| 282 | #ifdef CONFIG_STRAM_SWAP |
| 283 | /* if max_swap_size is negative (i.e. no stram_swap= option given), |
| 284 | * determine at run time whether to use ST-RAM swapping */ |
| 285 | if (max_swap_size < 0) |
| 286 | /* Use swapping if ST-RAM doesn't make up more than MAX_STRAM_FRACTION |
| 287 | * of total memory. In that case, the max. size is set to 16 MB, |
| 288 | * because ST-RAM can never be bigger than that. |
| 289 | * Also, never use swapping on a Hades, there's no separate ST-RAM in |
| 290 | * that machine. */ |
| 291 | max_swap_size = |
| 292 | (!MACH_IS_HADES && |
| 293 | (N_PAGES(stram_end-stram_start)*MAX_STRAM_FRACTION_DENOM <= |
| 294 | ((unsigned long)high_memory>>PAGE_SHIFT)*MAX_STRAM_FRACTION_NOM)) ? 16*1024*1024 : 0; |
| 295 | DPRINTK( "atari_stram_reserve_pages: max_swap_size = %d\n", max_swap_size ); |
| 296 | #endif |
| 297 | |
| 298 | /* always reserve first page of ST-RAM, the first 2 kB are |
| 299 | * supervisor-only! */ |
| 300 | if (!kernel_in_stram) |
| 301 | reserve_bootmem (0, PAGE_SIZE); |
| 302 | |
| 303 | #ifdef CONFIG_STRAM_SWAP |
| 304 | { |
| 305 | void *swap_data; |
| 306 | |
| 307 | start_mem = (void *) PAGE_ALIGN ((unsigned long) start_mem); |
| 308 | /* determine first page to use as swap: if the kernel is |
| 309 | in TT-RAM, this is the first page of (usable) ST-RAM; |
| 310 | otherwise just use the end of kernel data (= start_mem) */ |
| 311 | swap_start = !kernel_in_stram ? stram_start + PAGE_SIZE : start_mem; |
| 312 | /* decrement by one page, rest of kernel assumes that first swap page |
| 313 | * is always reserved and maybe doesn't handle swp_entry == 0 |
| 314 | * correctly */ |
| 315 | swap_start -= PAGE_SIZE; |
| 316 | swap_end = stram_end; |
| 317 | if (swap_end-swap_start > max_swap_size) |
| 318 | swap_end = swap_start + max_swap_size; |
| 319 | DPRINTK( "atari_stram_reserve_pages: swapping enabled; " |
| 320 | "swap=%p-%p\n", swap_start, swap_end); |
| 321 | |
| 322 | /* reserve some amount of memory for maintainance of |
| 323 | * swapping itself: one page for each 2048 (PAGE_SIZE/2) |
| 324 | * swap pages. (2 bytes for each page) */ |
| 325 | swap_data = start_mem; |
| 326 | start_mem += ((SWAP_NR(swap_end) + PAGE_SIZE/2 - 1) |
| 327 | >> (PAGE_SHIFT-1)) << PAGE_SHIFT; |
| 328 | /* correct swap_start if necessary */ |
| 329 | if (swap_start + PAGE_SIZE == swap_data) |
| 330 | swap_start = start_mem - PAGE_SIZE; |
| 331 | |
| 332 | if (!swap_init( start_mem, swap_data )) { |
| 333 | printk( KERN_ERR "ST-RAM swap space initialization failed\n" ); |
| 334 | max_swap_size = 0; |
| 335 | return; |
| 336 | } |
| 337 | /* reserve region for swapping meta-data */ |
| 338 | reserve_region(swap_data, start_mem); |
| 339 | /* reserve swapping area itself */ |
| 340 | reserve_region(swap_start + PAGE_SIZE, swap_end); |
| 341 | |
| 342 | /* |
| 343 | * If the whole ST-RAM is used for swapping, there are no allocatable |
| 344 | * dma pages left. But unfortunately, some shared parts of the kernel |
| 345 | * (particularly the SCSI mid-level) call __get_dma_pages() |
| 346 | * unconditionally :-( These calls then fail, and scsi.c even doesn't |
| 347 | * check for NULL return values and just crashes. The quick fix for |
| 348 | * this (instead of doing much clean up work in the SCSI code) is to |
| 349 | * pretend all pages are DMA-able by setting mach_max_dma_address to |
| 350 | * ULONG_MAX. This doesn't change any functionality so far, since |
| 351 | * get_dma_pages() shouldn't be used on Atari anyway anymore (better |
| 352 | * use atari_stram_alloc()), and the Atari SCSI drivers don't need DMA |
| 353 | * memory. But unfortunately there's now no kind of warning (even not |
| 354 | * a NULL return value) if you use get_dma_pages() nevertheless :-( |
| 355 | * You just will get non-DMA-able memory... |
| 356 | */ |
| 357 | mach_max_dma_address = 0xffffffff; |
| 358 | } |
| 359 | #endif |
| 360 | } |
| 361 | |
| 362 | void atari_stram_mem_init_hook (void) |
| 363 | { |
| 364 | mem_init_done = 1; |
| 365 | } |
| 366 | |
| 367 | |
| 368 | /* |
| 369 | * This is main public interface: somehow allocate a ST-RAM block |
| 370 | * There are three strategies: |
| 371 | * |
| 372 | * - If we're before mem_init(), we have to make a static allocation. The |
| 373 | * region is taken in the kernel data area (if the kernel is in ST-RAM) or |
| 374 | * from the start of ST-RAM (if the kernel is in TT-RAM) and added to the |
| 375 | * rsvd_stram_* region. The ST-RAM is somewhere in the middle of kernel |
| 376 | * address space in the latter case. |
| 377 | * |
| 378 | * - If mem_init() already has been called and ST-RAM swapping is enabled, |
| 379 | * try to get the memory from the (pseudo) swap-space, either free already |
| 380 | * or by moving some other pages out of the swap. |
| 381 | * |
| 382 | * - If mem_init() already has been called, and ST-RAM swapping is not |
| 383 | * enabled, the only possibility is to try with __get_dma_pages(). This has |
| 384 | * the disadvantage that it's very hard to get more than 1 page, and it is |
| 385 | * likely to fail :-( |
| 386 | * |
| 387 | */ |
| 388 | void *atari_stram_alloc(long size, const char *owner) |
| 389 | { |
| 390 | void *addr = NULL; |
| 391 | BLOCK *block; |
| 392 | int flags; |
| 393 | |
| 394 | DPRINTK("atari_stram_alloc(size=%08lx,owner=%s)\n", size, owner); |
| 395 | |
| 396 | size = ALIGN_IF_SWAP(size); |
| 397 | DPRINTK( "atari_stram_alloc: rounded size = %08lx\n", size ); |
| 398 | #ifdef CONFIG_STRAM_SWAP |
| 399 | if (max_swap_size) { |
| 400 | /* If swapping is active: make some free space in the swap |
| 401 | "device". */ |
| 402 | DPRINTK( "atari_stram_alloc: after mem_init, swapping ok, " |
| 403 | "calling get_region\n" ); |
| 404 | addr = get_stram_region( N_PAGES(size) ); |
| 405 | flags = BLOCK_INSWAP; |
| 406 | } |
| 407 | else |
| 408 | #endif |
| 409 | if (!mem_init_done) |
| 410 | return alloc_bootmem_low(size); |
| 411 | else { |
| 412 | /* After mem_init() and no swapping: can only resort to |
| 413 | * __get_dma_pages() */ |
| 414 | addr = (void *)__get_dma_pages(GFP_KERNEL, get_order(size)); |
| 415 | flags = BLOCK_GFP; |
| 416 | DPRINTK( "atari_stram_alloc: after mem_init, swapping off, " |
| 417 | "get_pages=%p\n", addr ); |
| 418 | } |
| 419 | |
| 420 | if (addr) { |
| 421 | if (!(block = add_region( addr, size ))) { |
| 422 | /* out of memory for BLOCK structure :-( */ |
| 423 | DPRINTK( "atari_stram_alloc: out of mem for BLOCK -- " |
| 424 | "freeing again\n" ); |
| 425 | #ifdef CONFIG_STRAM_SWAP |
| 426 | if (flags == BLOCK_INSWAP) |
| 427 | free_stram_region( SWAP_NR(addr), N_PAGES(size) ); |
| 428 | else |
| 429 | #endif |
| 430 | free_pages((unsigned long)addr, get_order(size)); |
| 431 | return( NULL ); |
| 432 | } |
| 433 | block->owner = owner; |
| 434 | block->flags |= flags; |
| 435 | } |
| 436 | return( addr ); |
| 437 | } |
| 438 | |
| 439 | void atari_stram_free( void *addr ) |
| 440 | |
| 441 | { |
| 442 | BLOCK *block; |
| 443 | |
| 444 | DPRINTK( "atari_stram_free(addr=%p)\n", addr ); |
| 445 | |
| 446 | if (!(block = find_region( addr ))) { |
| 447 | printk( KERN_ERR "Attempt to free non-allocated ST-RAM block at %p " |
| 448 | "from %p\n", addr, __builtin_return_address(0) ); |
| 449 | return; |
| 450 | } |
| 451 | DPRINTK( "atari_stram_free: found block (%p): size=%08lx, owner=%s, " |
| 452 | "flags=%02x\n", block, block->size, block->owner, block->flags ); |
| 453 | |
| 454 | #ifdef CONFIG_STRAM_SWAP |
| 455 | if (!max_swap_size) { |
| 456 | #endif |
| 457 | if (block->flags & BLOCK_GFP) { |
| 458 | DPRINTK("atari_stram_free: is kmalloced, order_size=%d\n", |
| 459 | get_order(block->size)); |
| 460 | free_pages((unsigned long)addr, get_order(block->size)); |
| 461 | } |
| 462 | else |
| 463 | goto fail; |
| 464 | #ifdef CONFIG_STRAM_SWAP |
| 465 | } |
| 466 | else if (block->flags & BLOCK_INSWAP) { |
| 467 | DPRINTK( "atari_stram_free: is swap-alloced\n" ); |
| 468 | free_stram_region( SWAP_NR(block->start), N_PAGES(block->size) ); |
| 469 | } |
| 470 | else |
| 471 | goto fail; |
| 472 | #endif |
| 473 | remove_region( block ); |
| 474 | return; |
| 475 | |
| 476 | fail: |
| 477 | printk( KERN_ERR "atari_stram_free: cannot free block at %p " |
| 478 | "(called from %p)\n", addr, __builtin_return_address(0) ); |
| 479 | } |
| 480 | |
| 481 | |
| 482 | #ifdef CONFIG_STRAM_SWAP |
| 483 | |
| 484 | |
| 485 | /* ------------------------------------------------------------------------ */ |
| 486 | /* Main Swapping Functions */ |
| 487 | /* ------------------------------------------------------------------------ */ |
| 488 | |
| 489 | |
| 490 | /* |
| 491 | * Initialize ST-RAM swap device |
| 492 | * (lots copied and modified from sys_swapon() in mm/swapfile.c) |
| 493 | */ |
| 494 | static int __init swap_init(void *start_mem, void *swap_data) |
| 495 | { |
| 496 | static struct dentry fake_dentry; |
| 497 | static struct vfsmount fake_vfsmnt; |
| 498 | struct swap_info_struct *p; |
| 499 | struct inode swap_inode; |
| 500 | unsigned int type; |
| 501 | void *addr; |
| 502 | int i, j, k, prev; |
| 503 | |
| 504 | DPRINTK("swap_init(start_mem=%p, swap_data=%p)\n", |
| 505 | start_mem, swap_data); |
| 506 | |
| 507 | /* need at least one page for swapping to (and this also isn't very |
| 508 | * much... :-) */ |
| 509 | if (swap_end - swap_start < 2*PAGE_SIZE) { |
| 510 | printk( KERN_WARNING "stram_swap_init: swap space too small\n" ); |
| 511 | return( 0 ); |
| 512 | } |
| 513 | |
| 514 | /* find free slot in swap_info */ |
| 515 | for( p = swap_info, type = 0; type < nr_swapfiles; type++, p++ ) |
| 516 | if (!(p->flags & SWP_USED)) |
| 517 | break; |
| 518 | if (type >= MAX_SWAPFILES) { |
| 519 | printk( KERN_WARNING "stram_swap_init: max. number of " |
| 520 | "swap devices exhausted\n" ); |
| 521 | return( 0 ); |
| 522 | } |
| 523 | if (type >= nr_swapfiles) |
| 524 | nr_swapfiles = type+1; |
| 525 | |
| 526 | stram_swap_info = p; |
| 527 | stram_swap_type = type; |
| 528 | |
| 529 | /* fake some dir cache entries to give us some name in /dev/swaps */ |
| 530 | fake_dentry.d_parent = &fake_dentry; |
| 531 | fake_dentry.d_name.name = "stram (internal)"; |
| 532 | fake_dentry.d_name.len = 16; |
| 533 | fake_vfsmnt.mnt_parent = &fake_vfsmnt; |
| 534 | |
| 535 | p->flags = SWP_USED; |
| 536 | p->swap_file = &fake_dentry; |
| 537 | p->swap_vfsmnt = &fake_vfsmnt; |
| 538 | p->swap_map = swap_data; |
| 539 | p->cluster_nr = 0; |
| 540 | p->next = -1; |
| 541 | p->prio = 0x7ff0; /* a rather high priority, but not the higest |
| 542 | * to give the user a chance to override */ |
| 543 | |
| 544 | /* call stram_open() directly, avoids at least the overhead in |
| 545 | * constructing a dummy file structure... */ |
| 546 | swap_inode.i_rdev = MKDEV( STRAM_MAJOR, STRAM_MINOR ); |
| 547 | stram_open( &swap_inode, MAGIC_FILE_P ); |
| 548 | p->max = SWAP_NR(swap_end); |
| 549 | |
| 550 | /* initialize swap_map: set regions that are already allocated or belong |
| 551 | * to kernel data space to SWAP_MAP_BAD, otherwise to free */ |
| 552 | j = 0; /* # of free pages */ |
| 553 | k = 0; /* # of already allocated pages (from pre-mem_init stram_alloc()) */ |
| 554 | p->lowest_bit = 0; |
| 555 | p->highest_bit = 0; |
| 556 | for( i = 1, addr = SWAP_ADDR(1); i < p->max; |
| 557 | i++, addr += PAGE_SIZE ) { |
| 558 | if (in_some_region( addr )) { |
| 559 | p->swap_map[i] = SWAP_MAP_BAD; |
| 560 | ++k; |
| 561 | } |
| 562 | else if (kernel_in_stram && addr < start_mem ) { |
| 563 | p->swap_map[i] = SWAP_MAP_BAD; |
| 564 | } |
| 565 | else { |
| 566 | p->swap_map[i] = 0; |
| 567 | ++j; |
| 568 | if (!p->lowest_bit) p->lowest_bit = i; |
| 569 | p->highest_bit = i; |
| 570 | } |
| 571 | } |
| 572 | /* first page always reserved (and doesn't really belong to swap space) */ |
| 573 | p->swap_map[0] = SWAP_MAP_BAD; |
| 574 | |
| 575 | /* now swapping to this device ok */ |
| 576 | p->pages = j + k; |
| 577 | swap_list_lock(); |
| 578 | nr_swap_pages += j; |
| 579 | p->flags = SWP_WRITEOK; |
| 580 | |
| 581 | /* insert swap space into swap_list */ |
| 582 | prev = -1; |
| 583 | for (i = swap_list.head; i >= 0; i = swap_info[i].next) { |
| 584 | if (p->prio >= swap_info[i].prio) { |
| 585 | break; |
| 586 | } |
| 587 | prev = i; |
| 588 | } |
| 589 | p->next = i; |
| 590 | if (prev < 0) { |
| 591 | swap_list.head = swap_list.next = p - swap_info; |
| 592 | } else { |
| 593 | swap_info[prev].next = p - swap_info; |
| 594 | } |
| 595 | swap_list_unlock(); |
| 596 | |
| 597 | printk( KERN_INFO "Using %dk (%d pages) of ST-RAM as swap space.\n", |
| 598 | p->pages << 2, p->pages ); |
| 599 | return( 1 ); |
| 600 | } |
| 601 | |
| 602 | |
| 603 | /* |
| 604 | * The swap entry has been read in advance, and we return 1 to indicate |
| 605 | * that the page has been used or is no longer needed. |
| 606 | * |
| 607 | * Always set the resulting pte to be nowrite (the same as COW pages |
| 608 | * after one process has exited). We don't know just how many PTEs will |
| 609 | * share this swap entry, so be cautious and let do_wp_page work out |
| 610 | * what to do if a write is requested later. |
| 611 | */ |
| 612 | static inline void unswap_pte(struct vm_area_struct * vma, unsigned long |
| 613 | address, pte_t *dir, swp_entry_t entry, |
| 614 | struct page *page) |
| 615 | { |
| 616 | pte_t pte = *dir; |
| 617 | |
| 618 | if (pte_none(pte)) |
| 619 | return; |
| 620 | if (pte_present(pte)) { |
| 621 | /* If this entry is swap-cached, then page must already |
| 622 | hold the right address for any copies in physical |
| 623 | memory */ |
| 624 | if (pte_page(pte) != page) |
| 625 | return; |
| 626 | /* We will be removing the swap cache in a moment, so... */ |
| 627 | set_pte(dir, pte_mkdirty(pte)); |
| 628 | return; |
| 629 | } |
| 630 | if (pte_val(pte) != entry.val) |
| 631 | return; |
| 632 | |
| 633 | DPRINTK("unswap_pte: replacing entry %08lx by new page %p", |
| 634 | entry.val, page); |
| 635 | set_pte(dir, pte_mkdirty(mk_pte(page, vma->vm_page_prot))); |
| 636 | swap_free(entry); |
| 637 | get_page(page); |
| 638 | inc_mm_counter(vma->vm_mm, rss); |
| 639 | } |
| 640 | |
| 641 | static inline void unswap_pmd(struct vm_area_struct * vma, pmd_t *dir, |
| 642 | unsigned long address, unsigned long size, |
| 643 | unsigned long offset, swp_entry_t entry, |
| 644 | struct page *page) |
| 645 | { |
| 646 | pte_t * pte; |
| 647 | unsigned long end; |
| 648 | |
| 649 | if (pmd_none(*dir)) |
| 650 | return; |
| 651 | if (pmd_bad(*dir)) { |
| 652 | pmd_ERROR(*dir); |
| 653 | pmd_clear(dir); |
| 654 | return; |
| 655 | } |
| 656 | pte = pte_offset_kernel(dir, address); |
| 657 | offset += address & PMD_MASK; |
| 658 | address &= ~PMD_MASK; |
| 659 | end = address + size; |
| 660 | if (end > PMD_SIZE) |
| 661 | end = PMD_SIZE; |
| 662 | do { |
| 663 | unswap_pte(vma, offset+address-vma->vm_start, pte, entry, page); |
| 664 | address += PAGE_SIZE; |
| 665 | pte++; |
| 666 | } while (address < end); |
| 667 | } |
| 668 | |
| 669 | static inline void unswap_pgd(struct vm_area_struct * vma, pgd_t *dir, |
| 670 | unsigned long address, unsigned long size, |
| 671 | swp_entry_t entry, struct page *page) |
| 672 | { |
| 673 | pmd_t * pmd; |
| 674 | unsigned long offset, end; |
| 675 | |
| 676 | if (pgd_none(*dir)) |
| 677 | return; |
| 678 | if (pgd_bad(*dir)) { |
| 679 | pgd_ERROR(*dir); |
| 680 | pgd_clear(dir); |
| 681 | return; |
| 682 | } |
| 683 | pmd = pmd_offset(dir, address); |
| 684 | offset = address & PGDIR_MASK; |
| 685 | address &= ~PGDIR_MASK; |
| 686 | end = address + size; |
| 687 | if (end > PGDIR_SIZE) |
| 688 | end = PGDIR_SIZE; |
| 689 | do { |
| 690 | unswap_pmd(vma, pmd, address, end - address, offset, entry, |
| 691 | page); |
| 692 | address = (address + PMD_SIZE) & PMD_MASK; |
| 693 | pmd++; |
| 694 | } while (address < end); |
| 695 | } |
| 696 | |
| 697 | static void unswap_vma(struct vm_area_struct * vma, pgd_t *pgdir, |
| 698 | swp_entry_t entry, struct page *page) |
| 699 | { |
| 700 | unsigned long start = vma->vm_start, end = vma->vm_end; |
| 701 | |
| 702 | do { |
| 703 | unswap_pgd(vma, pgdir, start, end - start, entry, page); |
| 704 | start = (start + PGDIR_SIZE) & PGDIR_MASK; |
| 705 | pgdir++; |
| 706 | } while (start < end); |
| 707 | } |
| 708 | |
| 709 | static void unswap_process(struct mm_struct * mm, swp_entry_t entry, |
| 710 | struct page *page) |
| 711 | { |
| 712 | struct vm_area_struct* vma; |
| 713 | |
| 714 | /* |
| 715 | * Go through process' page directory. |
| 716 | */ |
| 717 | if (!mm) |
| 718 | return; |
| 719 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
| 720 | pgd_t * pgd = pgd_offset(mm, vma->vm_start); |
| 721 | unswap_vma(vma, pgd, entry, page); |
| 722 | } |
| 723 | } |
| 724 | |
| 725 | |
| 726 | static int unswap_by_read(unsigned short *map, unsigned long max, |
| 727 | unsigned long start, unsigned long n_pages) |
| 728 | { |
| 729 | struct task_struct *p; |
| 730 | struct page *page; |
| 731 | swp_entry_t entry; |
| 732 | unsigned long i; |
| 733 | |
| 734 | DPRINTK( "unswapping %lu..%lu by reading in\n", |
| 735 | start, start+n_pages-1 ); |
| 736 | |
| 737 | for( i = start; i < start+n_pages; ++i ) { |
| 738 | if (map[i] == SWAP_MAP_BAD) { |
| 739 | printk( KERN_ERR "get_stram_region: page %lu already " |
| 740 | "reserved??\n", i ); |
| 741 | continue; |
| 742 | } |
| 743 | |
| 744 | if (map[i]) { |
| 745 | entry = swp_entry(stram_swap_type, i); |
| 746 | DPRINTK("unswap: map[i=%lu]=%u nr_swap=%ld\n", |
| 747 | i, map[i], nr_swap_pages); |
| 748 | |
| 749 | swap_device_lock(stram_swap_info); |
| 750 | map[i]++; |
| 751 | swap_device_unlock(stram_swap_info); |
| 752 | /* Get a page for the entry, using the existing |
| 753 | swap cache page if there is one. Otherwise, |
| 754 | get a clean page and read the swap into it. */ |
| 755 | page = read_swap_cache_async(entry, NULL, 0); |
| 756 | if (!page) { |
| 757 | swap_free(entry); |
| 758 | return -ENOMEM; |
| 759 | } |
| 760 | read_lock(&tasklist_lock); |
| 761 | for_each_process(p) |
| 762 | unswap_process(p->mm, entry, page); |
| 763 | read_unlock(&tasklist_lock); |
| 764 | shmem_unuse(entry, page); |
| 765 | /* Now get rid of the extra reference to the |
| 766 | temporary page we've been using. */ |
| 767 | if (PageSwapCache(page)) |
| 768 | delete_from_swap_cache(page); |
| 769 | __free_page(page); |
| 770 | #ifdef DO_PROC |
| 771 | stat_swap_force++; |
| 772 | #endif |
| 773 | } |
| 774 | |
| 775 | DPRINTK( "unswap: map[i=%lu]=%u nr_swap=%ld\n", |
| 776 | i, map[i], nr_swap_pages ); |
| 777 | swap_list_lock(); |
| 778 | swap_device_lock(stram_swap_info); |
| 779 | map[i] = SWAP_MAP_BAD; |
| 780 | if (stram_swap_info->lowest_bit == i) |
| 781 | stram_swap_info->lowest_bit++; |
| 782 | if (stram_swap_info->highest_bit == i) |
| 783 | stram_swap_info->highest_bit--; |
| 784 | --nr_swap_pages; |
| 785 | swap_device_unlock(stram_swap_info); |
| 786 | swap_list_unlock(); |
| 787 | } |
| 788 | |
| 789 | return 0; |
| 790 | } |
| 791 | |
| 792 | /* |
| 793 | * reserve a region in ST-RAM swap space for an allocation |
| 794 | */ |
| 795 | static void *get_stram_region( unsigned long n_pages ) |
| 796 | { |
| 797 | unsigned short *map = stram_swap_info->swap_map; |
| 798 | unsigned long max = stram_swap_info->max; |
| 799 | unsigned long start, total_free, region_free; |
| 800 | int err; |
| 801 | void *ret = NULL; |
| 802 | |
| 803 | DPRINTK( "get_stram_region(n_pages=%lu)\n", n_pages ); |
| 804 | |
| 805 | down(&stram_swap_sem); |
| 806 | |
| 807 | /* disallow writing to the swap device now */ |
| 808 | stram_swap_info->flags = SWP_USED; |
| 809 | |
| 810 | /* find a region of n_pages pages in the swap space including as much free |
| 811 | * pages as possible (and excluding any already-reserved pages). */ |
| 812 | if (!(start = find_free_region( n_pages, &total_free, ®ion_free ))) |
| 813 | goto end; |
| 814 | DPRINTK( "get_stram_region: region starts at %lu, has %lu free pages\n", |
| 815 | start, region_free ); |
| 816 | |
| 817 | err = unswap_by_read(map, max, start, n_pages); |
| 818 | if (err) |
| 819 | goto end; |
| 820 | |
| 821 | ret = SWAP_ADDR(start); |
| 822 | end: |
| 823 | /* allow using swap device again */ |
| 824 | stram_swap_info->flags = SWP_WRITEOK; |
| 825 | up(&stram_swap_sem); |
| 826 | DPRINTK( "get_stram_region: returning %p\n", ret ); |
| 827 | return( ret ); |
| 828 | } |
| 829 | |
| 830 | |
| 831 | /* |
| 832 | * free a reserved region in ST-RAM swap space |
| 833 | */ |
| 834 | static void free_stram_region( unsigned long offset, unsigned long n_pages ) |
| 835 | { |
| 836 | unsigned short *map = stram_swap_info->swap_map; |
| 837 | |
| 838 | DPRINTK( "free_stram_region(offset=%lu,n_pages=%lu)\n", offset, n_pages ); |
| 839 | |
| 840 | if (offset < 1 || offset + n_pages > stram_swap_info->max) { |
| 841 | printk( KERN_ERR "free_stram_region: Trying to free non-ST-RAM\n" ); |
| 842 | return; |
| 843 | } |
| 844 | |
| 845 | swap_list_lock(); |
| 846 | swap_device_lock(stram_swap_info); |
| 847 | /* un-reserve the freed pages */ |
| 848 | for( ; n_pages > 0; ++offset, --n_pages ) { |
| 849 | if (map[offset] != SWAP_MAP_BAD) |
| 850 | printk( KERN_ERR "free_stram_region: Swap page %lu was not " |
| 851 | "reserved\n", offset ); |
| 852 | map[offset] = 0; |
| 853 | } |
| 854 | |
| 855 | /* update swapping meta-data */ |
| 856 | if (offset < stram_swap_info->lowest_bit) |
| 857 | stram_swap_info->lowest_bit = offset; |
| 858 | if (offset+n_pages-1 > stram_swap_info->highest_bit) |
| 859 | stram_swap_info->highest_bit = offset+n_pages-1; |
| 860 | if (stram_swap_info->prio > swap_info[swap_list.next].prio) |
| 861 | swap_list.next = swap_list.head; |
| 862 | nr_swap_pages += n_pages; |
| 863 | swap_device_unlock(stram_swap_info); |
| 864 | swap_list_unlock(); |
| 865 | } |
| 866 | |
| 867 | |
| 868 | /* ------------------------------------------------------------------------ */ |
| 869 | /* Utility Functions for Swapping */ |
| 870 | /* ------------------------------------------------------------------------ */ |
| 871 | |
| 872 | |
| 873 | /* is addr in some of the allocated regions? */ |
| 874 | static int in_some_region(void *addr) |
| 875 | { |
| 876 | BLOCK *p; |
| 877 | |
| 878 | for( p = alloc_list; p; p = p->next ) { |
| 879 | if (p->start <= addr && addr < p->start + p->size) |
| 880 | return( 1 ); |
| 881 | } |
| 882 | return( 0 ); |
| 883 | } |
| 884 | |
| 885 | |
| 886 | static unsigned long find_free_region(unsigned long n_pages, |
| 887 | unsigned long *total_free, |
| 888 | unsigned long *region_free) |
| 889 | { |
| 890 | unsigned short *map = stram_swap_info->swap_map; |
| 891 | unsigned long max = stram_swap_info->max; |
| 892 | unsigned long head, tail, max_start; |
| 893 | long nfree, max_free; |
| 894 | |
| 895 | /* first scan the swap space for a suitable place for the allocation */ |
| 896 | head = 1; |
| 897 | max_start = 0; |
| 898 | max_free = -1; |
| 899 | *total_free = 0; |
| 900 | |
| 901 | start_over: |
| 902 | /* increment tail until final window size reached, and count free pages */ |
| 903 | nfree = 0; |
| 904 | for( tail = head; tail-head < n_pages && tail < max; ++tail ) { |
| 905 | if (map[tail] == SWAP_MAP_BAD) { |
| 906 | head = tail+1; |
| 907 | goto start_over; |
| 908 | } |
| 909 | if (!map[tail]) { |
| 910 | ++nfree; |
| 911 | ++*total_free; |
| 912 | } |
| 913 | } |
| 914 | if (tail-head < n_pages) |
| 915 | goto out; |
| 916 | if (nfree > max_free) { |
| 917 | max_start = head; |
| 918 | max_free = nfree; |
| 919 | if (max_free >= n_pages) |
| 920 | /* don't need more free pages... :-) */ |
| 921 | goto out; |
| 922 | } |
| 923 | |
| 924 | /* now shift the window and look for the area where as much pages as |
| 925 | * possible are free */ |
| 926 | while( tail < max ) { |
| 927 | nfree -= (map[head++] == 0); |
| 928 | if (map[tail] == SWAP_MAP_BAD) { |
| 929 | head = tail+1; |
| 930 | goto start_over; |
| 931 | } |
| 932 | if (!map[tail]) { |
| 933 | ++nfree; |
| 934 | ++*total_free; |
| 935 | } |
| 936 | ++tail; |
| 937 | if (nfree > max_free) { |
| 938 | max_start = head; |
| 939 | max_free = nfree; |
| 940 | if (max_free >= n_pages) |
| 941 | /* don't need more free pages... :-) */ |
| 942 | goto out; |
| 943 | } |
| 944 | } |
| 945 | |
| 946 | out: |
| 947 | if (max_free < 0) { |
| 948 | printk( KERN_NOTICE "get_stram_region: ST-RAM too full or fragmented " |
| 949 | "-- can't allocate %lu pages\n", n_pages ); |
| 950 | return( 0 ); |
| 951 | } |
| 952 | |
| 953 | *region_free = max_free; |
| 954 | return( max_start ); |
| 955 | } |
| 956 | |
| 957 | |
| 958 | /* setup parameters from command line */ |
| 959 | void __init stram_swap_setup(char *str, int *ints) |
| 960 | { |
| 961 | if (ints[0] >= 1) |
| 962 | max_swap_size = ((ints[1] < 0 ? 0 : ints[1]) * 1024) & PAGE_MASK; |
| 963 | } |
| 964 | |
| 965 | |
| 966 | /* ------------------------------------------------------------------------ */ |
| 967 | /* ST-RAM device */ |
| 968 | /* ------------------------------------------------------------------------ */ |
| 969 | |
| 970 | static int refcnt; |
| 971 | |
| 972 | static void do_stram_request(request_queue_t *q) |
| 973 | { |
| 974 | struct request *req; |
| 975 | |
| 976 | while ((req = elv_next_request(q)) != NULL) { |
| 977 | void *start = swap_start + (req->sector << 9); |
| 978 | unsigned long len = req->current_nr_sectors << 9; |
| 979 | if ((start + len) > swap_end) { |
| 980 | printk( KERN_ERR "stram: bad access beyond end of device: " |
| 981 | "block=%ld, count=%d\n", |
| 982 | req->sector, |
| 983 | req->current_nr_sectors ); |
| 984 | end_request(req, 0); |
| 985 | continue; |
| 986 | } |
| 987 | |
| 988 | if (req->cmd == READ) { |
| 989 | memcpy(req->buffer, start, len); |
| 990 | #ifdef DO_PROC |
| 991 | stat_swap_read += N_PAGES(len); |
| 992 | #endif |
| 993 | } |
| 994 | else { |
| 995 | memcpy(start, req->buffer, len); |
| 996 | #ifdef DO_PROC |
| 997 | stat_swap_write += N_PAGES(len); |
| 998 | #endif |
| 999 | } |
| 1000 | end_request(req, 1); |
| 1001 | } |
| 1002 | } |
| 1003 | |
| 1004 | |
| 1005 | static int stram_open( struct inode *inode, struct file *filp ) |
| 1006 | { |
| 1007 | if (filp != MAGIC_FILE_P) { |
| 1008 | printk( KERN_NOTICE "Only kernel can open ST-RAM device\n" ); |
| 1009 | return( -EPERM ); |
| 1010 | } |
| 1011 | if (refcnt) |
| 1012 | return( -EBUSY ); |
| 1013 | ++refcnt; |
| 1014 | return( 0 ); |
| 1015 | } |
| 1016 | |
| 1017 | static int stram_release( struct inode *inode, struct file *filp ) |
| 1018 | { |
| 1019 | if (filp != MAGIC_FILE_P) { |
| 1020 | printk( KERN_NOTICE "Only kernel can close ST-RAM device\n" ); |
| 1021 | return( -EPERM ); |
| 1022 | } |
| 1023 | if (refcnt > 0) |
| 1024 | --refcnt; |
| 1025 | return( 0 ); |
| 1026 | } |
| 1027 | |
| 1028 | |
| 1029 | static struct block_device_operations stram_fops = { |
| 1030 | .open = stram_open, |
| 1031 | .release = stram_release, |
| 1032 | }; |
| 1033 | |
| 1034 | static struct gendisk *stram_disk; |
| 1035 | static struct request_queue *stram_queue; |
| 1036 | static DEFINE_SPINLOCK(stram_lock); |
| 1037 | |
| 1038 | int __init stram_device_init(void) |
| 1039 | { |
| 1040 | if (!MACH_IS_ATARI) |
| 1041 | /* no point in initializing this, I hope */ |
| 1042 | return -ENXIO; |
| 1043 | |
| 1044 | if (!max_swap_size) |
| 1045 | /* swapping not enabled */ |
| 1046 | return -ENXIO; |
| 1047 | stram_disk = alloc_disk(1); |
| 1048 | if (!stram_disk) |
| 1049 | return -ENOMEM; |
| 1050 | |
| 1051 | if (register_blkdev(STRAM_MAJOR, "stram")) { |
| 1052 | put_disk(stram_disk); |
| 1053 | return -ENXIO; |
| 1054 | } |
| 1055 | |
| 1056 | stram_queue = blk_init_queue(do_stram_request, &stram_lock); |
| 1057 | if (!stram_queue) { |
| 1058 | unregister_blkdev(STRAM_MAJOR, "stram"); |
| 1059 | put_disk(stram_disk); |
| 1060 | return -ENOMEM; |
| 1061 | } |
| 1062 | |
| 1063 | stram_disk->major = STRAM_MAJOR; |
| 1064 | stram_disk->first_minor = STRAM_MINOR; |
| 1065 | stram_disk->fops = &stram_fops; |
| 1066 | stram_disk->queue = stram_queue; |
| 1067 | sprintf(stram_disk->disk_name, "stram"); |
| 1068 | set_capacity(stram_disk, (swap_end - swap_start)/512); |
| 1069 | add_disk(stram_disk); |
| 1070 | return 0; |
| 1071 | } |
| 1072 | |
| 1073 | |
| 1074 | |
| 1075 | /* ------------------------------------------------------------------------ */ |
| 1076 | /* Misc Utility Functions */ |
| 1077 | /* ------------------------------------------------------------------------ */ |
| 1078 | |
| 1079 | /* reserve a range of pages */ |
| 1080 | static void reserve_region(void *start, void *end) |
| 1081 | { |
| 1082 | reserve_bootmem (virt_to_phys(start), end - start); |
| 1083 | } |
| 1084 | |
| 1085 | #endif /* CONFIG_STRAM_SWAP */ |
| 1086 | |
| 1087 | |
| 1088 | /* ------------------------------------------------------------------------ */ |
| 1089 | /* Region Management */ |
| 1090 | /* ------------------------------------------------------------------------ */ |
| 1091 | |
| 1092 | |
| 1093 | /* insert a region into the alloced list (sorted) */ |
| 1094 | static BLOCK *add_region( void *addr, unsigned long size ) |
| 1095 | { |
| 1096 | BLOCK **p, *n = NULL; |
| 1097 | int i; |
| 1098 | |
| 1099 | for( i = 0; i < N_STATIC_BLOCKS; ++i ) { |
| 1100 | if (static_blocks[i].flags & BLOCK_FREE) { |
| 1101 | n = &static_blocks[i]; |
| 1102 | n->flags = 0; |
| 1103 | break; |
| 1104 | } |
| 1105 | } |
| 1106 | if (!n && mem_init_done) { |
| 1107 | /* if statics block pool exhausted and we can call kmalloc() already |
| 1108 | * (after mem_init()), try that */ |
| 1109 | n = kmalloc( sizeof(BLOCK), GFP_KERNEL ); |
| 1110 | if (n) |
| 1111 | n->flags = BLOCK_KMALLOCED; |
| 1112 | } |
| 1113 | if (!n) { |
| 1114 | printk( KERN_ERR "Out of memory for ST-RAM descriptor blocks\n" ); |
| 1115 | return( NULL ); |
| 1116 | } |
| 1117 | n->start = addr; |
| 1118 | n->size = size; |
| 1119 | |
| 1120 | for( p = &alloc_list; *p; p = &((*p)->next) ) |
| 1121 | if ((*p)->start > addr) break; |
| 1122 | n->next = *p; |
| 1123 | *p = n; |
| 1124 | |
| 1125 | return( n ); |
| 1126 | } |
| 1127 | |
| 1128 | |
| 1129 | /* find a region (by start addr) in the alloced list */ |
| 1130 | static BLOCK *find_region( void *addr ) |
| 1131 | { |
| 1132 | BLOCK *p; |
| 1133 | |
| 1134 | for( p = alloc_list; p; p = p->next ) { |
| 1135 | if (p->start == addr) |
| 1136 | return( p ); |
| 1137 | if (p->start > addr) |
| 1138 | break; |
| 1139 | } |
| 1140 | return( NULL ); |
| 1141 | } |
| 1142 | |
| 1143 | |
| 1144 | /* remove a block from the alloced list */ |
| 1145 | static int remove_region( BLOCK *block ) |
| 1146 | { |
| 1147 | BLOCK **p; |
| 1148 | |
| 1149 | for( p = &alloc_list; *p; p = &((*p)->next) ) |
| 1150 | if (*p == block) break; |
| 1151 | if (!*p) |
| 1152 | return( 0 ); |
| 1153 | |
| 1154 | *p = block->next; |
| 1155 | if (block->flags & BLOCK_KMALLOCED) |
| 1156 | kfree( block ); |
| 1157 | else |
| 1158 | block->flags |= BLOCK_FREE; |
| 1159 | return( 1 ); |
| 1160 | } |
| 1161 | |
| 1162 | |
| 1163 | |
| 1164 | /* ------------------------------------------------------------------------ */ |
| 1165 | /* /proc statistics file stuff */ |
| 1166 | /* ------------------------------------------------------------------------ */ |
| 1167 | |
| 1168 | #ifdef DO_PROC |
| 1169 | |
| 1170 | #define PRINT_PROC(fmt,args...) len += sprintf( buf+len, fmt, ##args ) |
| 1171 | |
| 1172 | int get_stram_list( char *buf ) |
| 1173 | { |
| 1174 | int len = 0; |
| 1175 | BLOCK *p; |
| 1176 | #ifdef CONFIG_STRAM_SWAP |
| 1177 | int i; |
| 1178 | unsigned short *map = stram_swap_info->swap_map; |
| 1179 | unsigned long max = stram_swap_info->max; |
| 1180 | unsigned free = 0, used = 0, rsvd = 0; |
| 1181 | #endif |
| 1182 | |
| 1183 | #ifdef CONFIG_STRAM_SWAP |
| 1184 | if (max_swap_size) { |
| 1185 | for( i = 1; i < max; ++i ) { |
| 1186 | if (!map[i]) |
| 1187 | ++free; |
| 1188 | else if (map[i] == SWAP_MAP_BAD) |
| 1189 | ++rsvd; |
| 1190 | else |
| 1191 | ++used; |
| 1192 | } |
| 1193 | PRINT_PROC( |
| 1194 | "Total ST-RAM: %8u kB\n" |
| 1195 | "Total ST-RAM swap: %8lu kB\n" |
| 1196 | "Free swap: %8u kB\n" |
| 1197 | "Used swap: %8u kB\n" |
| 1198 | "Allocated swap: %8u kB\n" |
| 1199 | "Swap Reads: %8u\n" |
| 1200 | "Swap Writes: %8u\n" |
| 1201 | "Swap Forced Reads: %8u\n", |
| 1202 | (stram_end - stram_start) >> 10, |
| 1203 | (max-1) << (PAGE_SHIFT-10), |
| 1204 | free << (PAGE_SHIFT-10), |
| 1205 | used << (PAGE_SHIFT-10), |
| 1206 | rsvd << (PAGE_SHIFT-10), |
| 1207 | stat_swap_read, |
| 1208 | stat_swap_write, |
| 1209 | stat_swap_force ); |
| 1210 | } |
| 1211 | else { |
| 1212 | #endif |
| 1213 | PRINT_PROC( "ST-RAM swapping disabled\n" ); |
| 1214 | PRINT_PROC("Total ST-RAM: %8u kB\n", |
| 1215 | (stram_end - stram_start) >> 10); |
| 1216 | #ifdef CONFIG_STRAM_SWAP |
| 1217 | } |
| 1218 | #endif |
| 1219 | |
| 1220 | PRINT_PROC( "Allocated regions:\n" ); |
| 1221 | for( p = alloc_list; p; p = p->next ) { |
| 1222 | if (len + 50 >= PAGE_SIZE) |
| 1223 | break; |
| 1224 | PRINT_PROC("0x%08lx-0x%08lx: %s (", |
| 1225 | virt_to_phys(p->start), |
| 1226 | virt_to_phys(p->start+p->size-1), |
| 1227 | p->owner); |
| 1228 | if (p->flags & BLOCK_GFP) |
| 1229 | PRINT_PROC( "page-alloced)\n" ); |
| 1230 | else if (p->flags & BLOCK_INSWAP) |
| 1231 | PRINT_PROC( "in swap)\n" ); |
| 1232 | else |
| 1233 | PRINT_PROC( "??)\n" ); |
| 1234 | } |
| 1235 | |
| 1236 | return( len ); |
| 1237 | } |
| 1238 | |
| 1239 | #endif |
| 1240 | |
| 1241 | |
| 1242 | /* |
| 1243 | * Local variables: |
| 1244 | * c-indent-level: 4 |
| 1245 | * tab-width: 4 |
| 1246 | * End: |
| 1247 | */ |